1. Field of Invention
The present invention relates to a high-power medium-voltage drive in electrical and electronic fields. More particularly, the present invention relates to a heat sink device suitable for use in a high-power medium-voltage drive power cell.
2. Description of Related Art
With the rapid development of modern electrical and electronic technology and microelectronic technologies, a high-voltage medium-power drive apparatus has increasingly wide applications, such as wind turbines, water pumps, compressors, rolling mills or the like in petrochemical, municipal water supply, die casting, power energy source industries.
There are vast categories for the high-power medium-voltage drive and there also are a variety of sorting methods related thereto. For example, the high-power medium-voltage drive may be classified as an AC-AC drive or an AC-DC-AC drive based on whether a DC current appears in a middle stage; as a current-type drive or a voltage-type drive based on the property of the DC portion; as a high-high drive or a high-low-high drive based on whether a low-voltage loop exists; and as a 2-level drive, a 3-level drive, a 5-level drive or a multi-level drive based on the number of the levels outputted by the drive. No matter what classifying manner is adopted, the power module with an independent function is one of the most important parts of the medium-voltage drive and is also the crucial part for implementing the medium-voltage variable frequency speed control. During the normal operation, the temperature of the power elements in the module continuously increases, so the heat dissipation design is an indispensable step in comprehensive consideration of the design specification in every aspect.
Currently, most of the heat dissipation designs for the high-power medium-voltage drive mostly adopt an aluminum extrusion heat sink. All portions of the power elements are placed on the heat sink. This structure causes high heat dissipation requirements. When a large heat sink, the distance between the power modules is relatively large and the layout is non-compact, which further causes inconvenience for the electrical connections and matching between the power elements and electrolytic capacitor assemblies. Moreover, the aluminum extrusion heat sink has a large volume, a heavy weight and a high cost, so that the aluminum extrusion heat sink is disadvantageous to the saving of system installation cost.
In view of the above, those in the industry are endeavoring to find ways to design a heat sink device suitable for use in a high-power medium-voltage drive power cell for effectively dissipating heat and meanwhile enabling the overall drive structure to be more compact.